Abstract In this study, poly(lactic acid) (PLA)/paraffin wax (PW) blends containing different amounts of PW were investigated. The blends were prepared by a twin-screw extruder using two different methods: conventional melt compounding extrusion and sub-critical gas-assisted processing (SGAP). Then, the blends and neat PLA were injection molded into ASTM 638 Type V tensile bars for evaluation. To observe the effects of the different melt compounding processes and the effects of paraffin wax added to the blends, the rheological properties, crystallization behavior, and thermal stability of the extruded blends, as well as the phase morphology and tensile properties of the injection molded tensile bars, were characterized. The results showed that the addition of paraffin wax yielded tremendous improvements in elongation compared to neat PLA. In addition, samples made by the sub-critical gas-assisted processing (SGAP) extrusion method exhibited more homogeneous phase morphologies and paraffin wax dispersion, better tensile properties and thermal stability, and more consistent material properties as compared to their conventionally compounded counterparts.

中文翻译：

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通过常规熔融复合和亚临界气体辅助加工 (SGAP) 制备的聚乳酸和石蜡混合物的机械性能和热特性

摘要 在这项研究中，研究了含有不同 PW 量的聚乳酸 (PLA)/石蜡 (PW) 共混物。该共混物是通过双螺杆挤出机使用两种不同的方法制备的：常规熔体复合挤出和亚临界气体辅助加工 (SGAP)。然后，将共混物和纯 PLA 注塑成 ASTM 638 V 型拉伸棒以进行评估。观察不同熔体复合工艺的影响和添加到共混物中石蜡的影响，挤出共混物的流变性能、结晶行为和热稳定性，以及注塑拉伸的相形态和拉伸性能酒吧，被表征。结果表明，与纯 PLA 相比，添加石蜡可显着提高伸长率。